Known electronic devices, generally of parallelepipedal form, comprise a support plate, including an electrical connection network, an integrated circuit chip mounted on one of the faces of the support plate and an encapsulation block in which the chip is embedded. The chip is linked to the network of the support plate by electrical connection elements such as balls, interposed between the support plate and the chip, or by electrical connection wires embedded in the encapsulation block.
Such electronic devices are mounted on printed circuit plates, generally via electrical connection elements such as balls, linking the electrical connection network of the support plates and the electrical connection network of the printed circuit plates.
When the chips generate radiofrequency signals that have to be transmitted or process received radiofrequency signals, the transmission or reception antennas are produced on the printed circuit plates. The electrical signals follow very long resistive paths which are formed by lines of the electrical connection network of the printed circuit plates, the electrical connection elements between the printed circuit plates and the support plates, lines of the electrical connection network of the support plates and the electrical connection elements between the support plates. Such paths further depend on the quality of the interconnections obtained from the fabrication.
The above provisions constitute a handicap notably when the necessary dimension of the antennas, for the transmission of radiofrequency signals at frequencies of the order of a gigahertz or above, even very much greater than a gigahertz, become reduced.